Elastomer series coupling damper for supercharger

ABSTRACT

A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub is mounted for concurrent rotation with the input shaft. The second hub is mounted for concurrent rotation with the rotor shaft. The first side coupling assembly has a first side coupling body and a first side elastomeric insert. The first side coupling body includes an inboard body portion having a first series of pockets and an outboard body portion having a second series of pockets. The first side elastomeric insert has a first and second plurality of lobes. The pockets of the first and second series of pockets are tangentially offset relative to each other and each receive respective first and second plurality of lobes therein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation U.S. patent application Ser. No.16/058,147 filed Aug. 8, 2018, which is a continuation of InternationalApplication No. PCT/US2016/047348 filed Aug. 17, 2017, which claims thebenefit of U.S. Patent Application No. 62/292,536 filed on Feb. 8, 2016and U.S. Patent Application No. 62/375,619 filed on Aug. 16, 2016. Thedisclosures of the above applications are incorporated herein byreference.

FIELD

The present disclosure relates generally to superchargers and moreparticularly to a coupling between an input shaft and a rotor shaft on asupercharger.

BACKGROUND

Rotary blowers of the type to which the present disclosure relates arereferred to as “superchargers” because they effectively super charge theintake of the engine. One supercharger configuration is generallyreferred to as a Roots-type blower that transfers volumes of air from aninlet port to an outlet port. A Roots-type blower includes a pair ofrotors which must be timed in relationship to each other, and therefore,are driven by meshed timing gears which are potentially subject toconditions such as gear rattle and bounce. Typically, a pulley and beltarrangement for a Roots blower supercharger is sized such that, at anygiven engine speed, the amount of air being transferred into the intakemanifold is greater than the instantaneous displacement of the engine,thus increasing the air pressure within the intake manifold andincreasing the power density of the engine.

In some examples, superchargers such as the Roots-type blower can createunwanted noise. For example, Roots-type blower noise may be classifiedas either of two types. The first is solid borne noise caused byrotation of timing gears and rotor shaft bearings subjected tofluctuating loads (the firing pulses of the engine), and the second isfluid borne noise caused by fluid flow characteristics, such as rapidchanges in fluid (air) velocity. The present disclosure is primarilydirected toward the solid borne noise. More particularly the presentdisclosure can minimize the “bounce” of the timing gears during times ofrelatively low speed operation, when the blower rotors are not “underload”. In this regard, it is important to isolate the fluctuating inputto the supercharger from the timing gears. In other examples it isdesirable to account for misalignment and/or runout between the inputshaft and rotor shaft. In some operating conditions, decoupling thesupercharger inertia from the belt system can help reduce unwanted noisegenerated in the belt system.

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

SUMMARY

A coupling assembly arranged between an input shaft and a rotor shaft ofa supercharger includes a first hub, a second hub, a first side couplingassembly, a second side coupling assembly, a central hub and a pluralityof coupler pins. The first hub is mounted for concurrent rotation withthe input shaft. The second hub is mounted for concurrent rotation withthe rotor shaft. The first side coupling assembly has a first sidecoupling body and a first side elastomeric insert. The first sidecoupling body includes an inboard body portion and an outboard bodyportion. The inboard body portion has a first series of pockets. Theoutboard body portion has a second series of pockets. The first sideelastomeric insert has a first and second plurality of lobes. Thepockets of the first and second series of pockets are tangentiallyoffset relative to each other and each receive respective first andsecond plurality of lobes therein. The second side coupling assembly hasa second side coupling body and a second side elastomeric insert. Thesecond side coupling body includes an inboard body portion and anoutboard body portion. The inboard body portion has a third series ofpockets. The outboard body portion has a fourth series of pockets. Thesecond side elastomeric insert has a third and fourth plurality oflobes. The pockets of the third and fourth series of pockets aretangentially offset relative to each other and each receive respectivethird and fourth lobes therein. The central hub is disposed intermediatethe first and second side coupling assemblies. The central hub definescentral hub bores therein. The plurality of coupler pins are received inthe central hub bores and extend on one end into the first plurality oflobes and on a second end into the third plurality of lobes. The firstand second side elastomeric inserts provide dampening between (i) thefirst side coupling body and the central hub and (ii) the second sidecoupling body and the central hub.

According to additional features, the first hub is configured to couplebetween the input shaft and the first side coupling assembly. The firsthub has a first plurality of hub pins extending therefrom. The secondhub is configured to couple between the rotor shaft and the second sidecoupling assembly. The second hub has a second plurality of hub pinsextending therefrom. The central hub further defines arcuate passagesformed therein and configured to at least partially receive the firsthub pins and the second hub pins.

According to other features, the first side coupling body defines aplurality of passages having an oval shape and the first sideelastomeric insert defines a plurality of openings having a circularshape. The second side coupling body defines a plurality of passageshaving an oval shape and the second side elastomeric insert defines aplurality of openings having a circular shape. The plurality of couplerpins and the first plurality of hub pins are permitted to travel withinthe boundary of the oval passages in the first side coupling body whilethe first side elastomeric insert absorbs torsional loads. The pluralityof coupler pins and the second plurality of hub pins are permitted totravel within the boundary of the oval passages in the second sidecoupling body while the second side elastomeric insert absorbs torsionalloads. The first and second side elastomeric inserts can be formed ofmolded rubber such as hydrogenated nitrile butadiene rubber (HNBR). Thefirst and second side coupling bodies are formed of one of Polyetherether ketone (PEEK) and glass-filled molded nylon such as Nylon 46 with30% glass fiber.

A coupling assembly according to another example of the presentdisclosure is arranged between an input shaft and a rotor shaft of asupercharger includes a first side coupling assembly, a second sidecoupling assembly, a central hub and a plurality of coupler pins. Thefirst side coupling assembly has a first side coupling body and a firstside elastomeric insert. The first side coupling body includes aninboard body portion and an outboard body portion. The inboard bodyportion has a first series of pockets and a first series of passages.The outboard body portion has a second series of pockets and a secondseries of passages. The first side elastomeric insert has a first andsecond plurality of lobes. The pockets of the first and second series ofpockets are tangentially offset relative to each other and each receiverespective first and second plurality of lobes therein. The second sidecoupling assembly has a second side coupling body and a second sideelastomeric insert. The second side coupling body includes an inboardbody portion and an outboard body portion. The inboard body portion hasa third series of pockets and a third series of passages. The outboardbody portion has a fourth series of pockets and a fourth series ofpassages. The second side elastomeric insert has a third and fourthplurality of lobes. The pockets of the third and fourth series ofpockets are tangentially offset relative to each other and each receiverespective third and fourth lobes therein. The central hub is disposedintermediate the first and second side coupling assemblies. The centralhub defines central hub bores therein. The plurality of coupler pins arereceived in the central hub bores and extend on one end into the firstplurality of lobes and on a second end into the third plurality oflobes. The plurality of coupler pins compress the first and second sideelastomeric inserts providing dampening between (i) the first sidecoupling body and the central hub and (ii) the second side coupling bodyand the central hub.

According to other features, the first series of passages have an ovalshape and the first side elastomeric insert defines a series of openingshaving a circular shape. The second series of passages have an ovalshape. The second side elastomeric insert defines a series of openingshaving a circular shape. The plurality of coupler pins are permitted totravel within the boundary of the oval passages in the first sidecoupling body while the first side elastomeric insert absorbs torsionalloads. The plurality of coupler pins are permitted to travel within theboundary of the oval passages in the second side coupling body while thesecond side elastomeric insert absorbs torsional loads. The first andsecond side elastomeric inserts can be formed of HNBR. The first andsecond side coupling bodies are formed of one of PEEK and glass-filledmolded nylon such as Nylon 46 with 30% glass fiber.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a schematic illustration of an intake manifold assembly havinga positive displacement blower or supercharger constructed in accordanceto one example of the present disclosure;

FIG. 2 is an enlarged, fragmentary, axial cross-section of the inputsection of the supercharger of FIG. 1 and having a coupling assemblyused to couple an input shaft and a rotor shaft and constructed inaccordance to one example of the present disclosure;

FIG. 3 is front perspective view of the coupling assembly of FIG. 2;

FIG. 4 is an exploded side view of the coupling assembly of FIG. 3;

FIG. 5 is an exploded, partially assembled side view of the couplingassembly of FIG. 2;

FIG. 6 is perspective view of the coupling assembly of FIG. 3 and shownwith a first hub removed;

FIG. 7 is a perspective view of the first side coupling assembly,central hub, coupler pins and first hub pins;

FIG. 8 is a perspective view of the coupling assembly of FIG. 6 andshown with the first hub removed and the first side coupling bodyremoved;

FIG. 9 is a perspective view of the first side coupling body; and

FIG. 10 is a perspective view of the first side coupling inserts.

DETAILED DESCRIPTION

With initial reference to FIG. 1, a schematic illustration of anexemplary intake manifold assembly, including a Roots blowersupercharger and bypass valve arrangement is shown. An engine 10 caninclude a plurality of cylinders 12, and a reciprocating piston 14disposed within each cylinder and defining an expandable combustionchamber 16. The engine 10 can include intake and exhaust manifoldassemblies 18 and 20, respectively, for directing combustion air to andfrom the combustion chamber 16, by way of intake and exhaust valves 22and 24, respectively.

The intake manifold assembly 18 can include a positive displacementrotary blower 26, or supercharger of the Roots type. Further descriptionof the rotary blower 26 may be found in commonly owned U.S. Pat. Nos.5,078,583 and 5,893,355, which are expressly incorporated herein byreference. The blower 26 includes a pair of rotors 28 and 29, each ofwhich includes a plurality of meshed lobes. The rotors 28 and 29 aredisposed in a pair of parallel, transversely overlapping cylindricalchambers 28 c and 29 c, respectively. The rotors 28 and 29 may be drivenmechanically by engine crankshaft torque transmitted thereto in a knownmanner, such as by a drive belt (not specifically shown). The mechanicaldrive rotates the blower rotors 28 and 29 at a fixed ratio, relative tocrankshaft speed, such that the displacement of the blower 26 is greaterthan the engine displacement, thereby boosting or supercharging the airflowing to the combustion chambers 16.

The blower 26 can include an inlet port 30 which receives air orair-fuel mixture from an inlet duct or passage 32, and further includesa discharge or outlet port 34, directing the charged air to the intakevalves 22 by means of a duct 36. The inlet duct 32 and the dischargeduct 36 are interconnected by means of a bypass passage, shownschematically at reference 38. If the engine 10 is of the Otto cycletype, a throttle valve 40 can control air or air-fuel mixture flowinginto the intake duct 32 from a source, such as ambient or atmosphericair, in a well know manner. Alternatively, the throttle valve 40 may bedisposed downstream of the supercharger 26.

A bypass valve 42 is disposed within the bypass passage 38. The bypassvalve 42 can be moved between an open position and a closed position bymeans of an actuator assembly 44. The actuator assembly 44 can beresponsive to fluid pressure in the inlet duct 32 by a vacuum line 46.The actuator assembly 44 is operative to control the superchargingpressure in the discharge duct 36 as a function of engine power demand.When the bypass valve 42 is in the fully open position, air pressure inthe duct 36 is relatively low, but when the bypass valve 42 is fullyclosed, the air pressure in the duct 36 is relatively high. Typically,the actuator assembly 44 controls the position of the bypass valve 42 bymeans of a suitable linkage. The bypass valve 42 shown and describedherein is merely exemplary and other configurations are contemplated. Inthis regard, a modular (integral) bypass, an electronically operatedbypass, or no bypass may be used.

With specific reference now to FIG. 2, an input section 48 of the blower26 is shown. The input section 48 can include a housing member 50, whichforms a forward end of the chambers 28 c and 29 c. Attached to thehousing member 50 is a forward housing 52 within which is disposed aninput shaft 54. The input shaft 54 is supported within the forwardhousing 52 by at least one bearing 56. Rotatably supported by thehousing member 50 is a rotor shaft 60, upon which is mounted the blowerrotor 28 (see FIG. 1). A coupling assembly 62 couples the input shaft 54to the rotor shaft 60. In one example, a first hub 64 can couple theinput shaft 54 to the coupling assembly 62 on a first end and a secondhub 66 can couple the rotor shaft 60 to the coupling assembly 62 on anopposite end. While not specifically shown, a first timing gear may bemounted on a forward end of the rotor shaft. The first timing gear maydefine teeth that are in meshed engagement with gear teeth of a secondtiming gear that is mounted on the second rotor shaft. The second rotorshaft would be in driving engagement with the blower rotor 29.

In one configuration, positive torque is transmitted from an internalcombustion engine (of the periodic combustion type) to the input shaft54 by any suitable drive means, such as a belt and pulley drive system(not shown herein). Torque is transmitted from the input shaft 54 to therotor shaft 60 through the coupling assembly 62. The coupling assembly62 of the present disclosure provides torsional damping and can furtheraccount for misalignment between the input shaft 54 and the rotor shaft60. When the engine 10 is driving the timing gears and the blower rotors28 and 29, such is considered to be transmission of positive torque. Onthe other hand, whenever the momentum of the rotors 28 and 29 overrunsthe input from the input shaft 54, such is considered to be thetransmission of negative torque.

With additional reference now to FIGS. 3-10, the coupling assembly 62constructed in accordance to one example of the present disclosure willbe described in greater detail. The coupling assembly 62 can generallyinclude a first side coupling assembly 70, a second side couplingassembly 80, a central hub 86, and a plurality of coupler pins 88 (FIG.4). The first side coupling assembly 70 can include a first sidecoupling body 90 and a first side elastomeric insert 92. As will bedescribed with respect to FIGS. 6-8 and 10, the first side elastomericinsert 92 can collectively be defined by a first and a secondtangentially offset cloverleaf members 92A and 92B. The first cloverleafmember 92A has a plurality of first lobes 93A. The second cloverleafmember 92B has a plurality of second lobes 93B. The lobes 93A aretangentially offset from the lobes 93B (see FIG. 10). The second sidecoupling assembly 80 can include a second side coupling body 94 and asecond side elastomeric insert 96. The second side elastomeric insert 96can collectively be defined by first and a second tangentially offsetcloverleaf members 96A and 96B. The first cloverleaf member 96A has aplurality of third lobes 97A. The second cloverleaf member 96B has aplurality of fourth lobes 97B. In the example shown, the first andsecond coupling assemblies 70 and 80 are constructed similarly. All ofthe coupler pins 88 are also constructed similarly.

With particular reference now to FIGS. 4-8, the first side couplingassembly 70 will be described. The first side coupling body 90 generallyincludes an outboard body portion 100 and an inboard body portion 102.The first and second side coupling bodies 90 and 94 can have acylindrical outer shape. In this regard, the outboard and inboard bodyportions 100 and 102 can have a cylindrical outer shape and be molded asa unitary component.

With specific reference to FIGS. 5, 6 and 9, the first side couplingbody 90 further defines a central bore 112, a first plurality of pocketsor openings 116A, and a second plurality of pockets or openings 116B(FIG. 9). The first plurality of openings 116A (FIG. 5) are configuredto accept the plurality of lobes 93A of the first cloverleaf member 92Aof the first side elastomeric insert 92. Similarly, the second pluralityof openings 116B (FIGS. 6 and 9) are configured to accept the pluralityof lobes 93B of the second cloverleaf member 92B of the first sideelastomeric insert 92. The openings 116A, 116B (FIG. 6) and respectivelobes 93A, 93B accommodate radial translation of the respective couplerpins 88 extending from the central hub 86 and hub pins 222 (FIG. 4)extending from the first hub 64 (FIG. 4).

Passages 117A and 117B (FIG. 9) are defined through the first sidecoupling body 90. The passages 117A and 117B are oval or oblong toaccommodate radial movement of the respective coupler pins 88 and hubpins 222. It will be appreciated that during movement of the pins 88 and222 within the oblong openings 117A and 117B relative to the first sidecoupling body 90, the plurality of lobes 93A and 93B compress andprovide dampening.

A plurality of tabs 118 (FIG. 9) can extend into the central bore 112.In one example, the tabs 118 can provide a gripping surface for a toolwhen removing components of the coupling assembly 62. While the exampleshown has three tabs, one, two or more than three may be provided. Thefirst side coupling body 90 can be formed of any suitable lightweightdurable material such as, but not limited to, Polyether ether ketone(PEEK) or glass-filled molded nylon such as Nylon 46 with 30% glassfiber.

With particular reference to FIG. 10, the first side elastomeric insert92 has a series of pin openings 130A and 130B therein. The respectiveplurality of lobes 93A and 93B can extend from a central hub 131. Theseries of openings 130A can receive the pins 88 while the series ofopenings 130B can receive the pins 222. The series of openings 130A and130B are cylindrical in shape. In this regard, the respective couplerpins 88 and hub pins 222 are permitted to travel within the boundary ofthe oval openings 117A, 117B while the coupler pins 88 and hub pins 222compress the plurality of lobes 93A and 93B at the openings 130A, 130Bto absorb torsional loads. In one example the first side elastomericinsert 92 can be formed of molded rubber such as hydrogenated nitrilebutadiene rubber (HNBR).

The second side coupling assembly 80 can be constructed similarly to thefirst side coupling assembly 70. In one configuration the first andsecond side coupling assemblies 70 and 80 can be identical. The secondside coupling body 94 further defines a central bore 120 (FIG. 5), athird plurality of pockets or openings 122A and a fourth plurality ofpockets or openings 122B. The third plurality of openings 122A areconfigured to accept the plurality of lobes 97A of the first cloverleafmember 96A of the second side elastomeric insert 96. Similarly, thefourth plurality of openings 122B are configured to accept the pluralityof lobes 97B of the second cloverleaf member 96B of the second sideelastomeric insert 96. The coupler pins 88 and hub pins 242 arepermitted to travel within the boundaries of oval passages 127B and127A, respectively (FIG. 5). The openings 122A, 122B and respectivelobes 96A, 96B accommodate radial translation of the respective couplerpins 88 extending from the central hub 86 and hub pins 224 (FIGS. 4 and5) extending from the second hub 66 (FIG. 4). As shown in FIG. 4, thesecond side elastomeric assembly 96 has a series of pin openings 126Aand 126B therein. It will be appreciated that during movement of thepins 88 and 224 within oblong openings 127A and 127B relative to thesecond side coupling body 94, the plurality of lobes 97A and 97Bcompress at the pin openings 126A and 126B to absorb torsional load andprovide dampening.

The second side coupling body 94 can be formed of any suitablelightweight durable material such as, but not limited to, PEEK orglass-filled molded nylon such as Nylon 46 with 30% glass fiber. Thesecond side elastomeric insert 96 can be formed of molded rubber such asHNBR.

As will become appreciated from the following discussion, the couplerpins 88 can bear against the surfaces defined by the openings 130B and126B of the respective first and second elastomeric inserts 92 and 96.The elastomeric material of the first and second elastomeric inserts 92and 96 can absorb the rotational energy from the coupler pins 88 duringoperation of the rotary blower 26 to provide dampening. Additionally,the hub pins 222 and 242 are also (alternately with the coupler pins 88)received by the openings 130A and 126A of the respective first andsecond elastomeric inserts 92 and 134. The elastomeric material of thefirst and second elastomeric inserts 92 and 96 can absorb the rotationalenergy from the hub pins 222 and 242 during operation of the rotaryblower 26 to provide dampening.

With particular reference to FIG. 4, the central hub 86 includes acentral hub body 188 having central bore 190, a series of alternatelyarranged bores 192 and arcuate passages 194. The central hub 86 can beformed of steel. The bores 192 can be configured to receive the couplerpins 88. The arcuate passages 194 can be configured to accommodate hubpins 222 and 242 associated with the first and second hubs 64 and 66.

The foregoing description of the examples has been provided for purposesof illustration and description. It is not intended to be exhaustive orto limit the disclosure. Individual elements or features of a particularexample are generally not limited to that particular example, but, whereapplicable, are interchangeable and can be used in a selected example,even if not specifically shown or described. The same may also be variedin many ways. Such variations are not to be regarded as a departure fromthe disclosure, and all such modifications are intended to be includedwithin the scope of the disclosure.

What is claimed is:
 1. A coupling assembly arranged between an inputshaft and a rotor shaft of a supercharger, the coupling assemblycomprising: a first side coupling assembly having (i) a first sidecoupling body and (ii) a first side elastomeric insert, the first sideelastomeric insert having a first and second plurality of lobes, thepockets of the first and second series of pockets being tangentiallyoffset relative to each other and each receiving respective first andsecond plurality of lobes therein; and a second side coupling assemblyhaving (i) a second side coupling body and (ii) a second sideelastomeric insert, the second side elastomeric insert having a thirdand fourth plurality of lobes, the pockets of the third and fourthseries of pockets being tangentially offset relative to each other andeach receiving respective third and fourth lobes therein.
 2. Thecoupling assembly of claim 1 wherein the coupling assembly furthercomprises a first hub mounted for concurrent rotation with the inputshaft and a second hub mounted for concurrent rotation with the rotorshaft.
 3. The coupling assembly of claim 1 wherein the coupling assemblyfurther comprises of a central hub disposed intermediate the first andsecond side coupling assemblies, the central hub defining central hubbores therein; and a plurality of coupler pins received in the centralhub bores and extending on one end into the first plurality of lobes andon a second end into the third plurality of lobes.
 4. The couplingassembly of claim 1 wherein the first and second side elastomericinserts provide dampening between (i) the first side coupling body andthe central hub and (ii) the second side coupling body and the centralhub.
 5. The coupling assembly of claim 1 wherein the first hub isconfigured to couple between the input shaft and the first side couplingassembly, the first hub having a first plurality of hub pins extendingtherefrom and wherein the second hub is configured to couple between therotor shaft and the second side coupling assembly, the second hub havinga second plurality of hub pins extending therefrom.
 6. The couplingassembly of claim 5 wherein the central hub further defines arcuatepassages formed therein configured to at least partially receive thefirst hub pins and the second hub pins.
 7. The coupling assembly ofclaim 6 wherein the first side coupling body defines a plurality ofpassages having an oval shape and the first side elastomeric insertdefines a plurality of openings having a circular shape.
 8. The couplingassembly of claim 7 wherein the second side coupling body defines aplurality of passages having an oval shape and the second sideelastomeric insert defines a plurality of openings having a circularshape.
 9. The coupling assembly of claim 8 wherein the plurality ofcoupler pins and the first plurality of hub pins are permitted to travelwithin the boundary of the oval passages in the first side coupling bodywhile the first side elastomeric insert absorbs torsional loads.
 10. Thecoupling assembly of claim 9 wherein the plurality of coupler pins andthe second plurality of hub pins are permitted to travel within theboundary of the oval passages in the second side coupling body while thesecond side elastomeric insert absorbs torsional loads.
 11. A couplingassembly arranged between an input shaft and a rotor shaft of asupercharger, the coupling assembly comprising: a first side couplingassembly having (i) a first side coupling body and (ii) a first sideelastomeric insert, the first side elastomeric insert having a first andsecond plurality of lobes, the pockets of the first and second series ofpockets being tangentially offset relative to each other and eachreceiving respective first and second plurality of lobes therein; and asecond side coupling assembly having (i) a second side coupling body and(ii) a second side elastomeric insert, the second side elastomericinsert having a third and fourth plurality of lobes, the pockets of thethird and fourth series of pockets being tangentially offset relative toeach other and each receiving respective third and fourth lobes therein.12. The coupling assembly of claim 11 wherein the coupling assemblyfurther comprises a first hub mounted for concurrent rotation with theinput shaft and a second hub mounted for concurrent rotation with therotor shaft.
 13. The coupling assembly of claim 11 wherein the couplingassembly further comprises a central hub disposed intermediate the firstand second side coupling assemblies, the central hub defining centralhub bores therein; and a plurality of coupler pins received in thecentral hub bores and extending on one end through the first series ofpassages and into the first plurality of lobes and on a second endthrough the third series of passages into the third plurality of lobes.14. The coupling assembly of claim 11 wherein the plurality of couplerpins compress the first and second side elastomeric inserts providedampening between (i) the first side coupling body and the central huband (ii) the second side coupling body and the central hub.
 15. Thecoupling assembly of claim 11 wherein the first series of passages havean oval shape and the first side elastomeric insert defines a series ofopenings having a circular shape.
 16. The coupling assembly of claim 15wherein second series of passages have an oval shape and the second sideelastomeric insert defines a series of openings having a circular shape.17. The coupling assembly of claim 16 wherein the plurality of couplerpins are permitted to travel within the boundary of the oval passages inthe first side coupling body while the first side elastomeric insertabsorbs torsional loads.
 18. The coupling assembly of claim 17 whereinthe plurality of coupler pins are permitted to travel within theboundary of the oval passages in the second side coupling body while thesecond side elastomeric insert absorbs torsional loads.
 19. The couplingassembly of claim 11 wherein the central hub comprises a plurality oftabs extending into a central bore thereof, the plurality of tabsconfigured to provide a gripping surface for a tool.
 20. The couplingassembly of claim 11 wherein the first and second plurality of lobes ofthe first side elastomeric insert and the third and fourth plurality oflobes of the second side elastomeric insert comprise tangentially offsetfirst and second cloverleaf members.